Glass beads catalyzed depolymerization of poplar wood lignin into low molecular weight products
In this work, a kind of non-precious glass bead catalyst is prepared by a subcritical water treatment method for depolymerizing poplar lignin. The subcritical water treatment time significantly affects the surface morphology, surface area, and the active metal content of the glass bead catalysts. Flaky and fibrous morphologies are found on the glass bead surface after being treated for 60 min and 120 min, respectively. Based on the GC-MS results of monomeric products, the glass beads treated for 60 min have higher catalytic activity compared to 120 min. The characterization results of lignin residues suggest that the glass beads are effective to prevent the repolymerization of lignin. Furthermore, the glass bead catalysts can be recycled to catalyze depolymerization lignin, and the monomeric products yield remains above 12 wt%.